diff --git a/05_sumAll/sumAll.js b/05_sumAll/sumAll.js
index 8ee567f..f578c17 100644
--- a/05_sumAll/sumAll.js
+++ b/05_sumAll/sumAll.js
@@ -1,5 +1,5 @@
 const sumAll = function(a, b) {
-    if (a < 0 || b < 0) {
+    if (a < 0 || b < 0 || typeof(a) != "number"|| typeof(b) != "number") {
         return "ERROR";
     }
     let c, sum = 0;
diff --git a/05_sumAll/sumAll.spec.js b/05_sumAll/sumAll.spec.js
index 7927aae..a171e5f 100644
--- a/05_sumAll/sumAll.spec.js
+++ b/05_sumAll/sumAll.spec.js
@@ -13,10 +13,10 @@ describe('sumAll', () => {
   test('returns ERROR with negative numbers', () => {
     expect(sumAll(-10, 4)).toEqual('ERROR');
   });
-  test.skip('returns ERROR with non-number parameters', () => {
+  test('returns ERROR with non-number parameters', () => {
     expect(sumAll(10, "90")).toEqual('ERROR');
   });
-  test.skip('returns ERROR with non-number parameters', () => {
+  test('returns ERROR with non-number parameters', () => {
     expect(sumAll(10, [90, 1])).toEqual('ERROR');
   });
 });